An organic light emitting diode (OLED) has a structure in which a functional organic layer is interposed between a cathode and an anode, and produces highly energetic excitons by recombination of holes injected from the anode with electrons injected from the cathode. The produced excitons are transferred to a ground state to generate light with a specific wavelength. Organic light emitting diodes have advantages of self-luminescence, fast response, wide viewing angle, ultra-slimness, high-definition, and durability.
However, organic light emitting diodes have a problem of deterioration in performance and lifespan due to oxidation of organic materials and/or electrode materials caused by moisture or oxygen from outside or internally or externally generated outgases. To overcome this problem, there have been proposed methods of applying photocurable sealing agents to a substrate with organic light emitting diodes, attaching transparent or opaque desiccants thereto, or forming fits thereon.
By way of example, Korean Patent Laid-open Publication No. 2006-0084978 discloses an organic light emitting diode encapsulation structure which uses a protective film for sealing formed of one of silicon compounds and polymer resins, as a waterproofing material.